Merge pull request #1262 from trapexit/readdir-errs

Rework thread pool queue depth impl

libfuse/include/fuse_dirents.h

@@ -64,10 +64,10 @@ int  fuse_dirents_add_plus(fuse_dirents_t      *d,
                            const fuse_entry_t  *entry,
                            const struct stat   *st);
 int  fuse_dirents_add_linux(fuse_dirents_t         *d,
-                            const struct linux_dirent64 *de,
+                            const linux_dirent64_t *de,
                             const uint64_t          namelen);
 int  fuse_dirents_add_linux_plus(fuse_dirents_t         *d,
-                                 const struct linux_dirent64 *de,
+                                 const linux_dirent64_t *de,
                                  const uint64_t          namelen,
                                  const fuse_entry_t     *entry,
                                  const struct stat      *st);

libfuse/include/linux_dirent64.h

@@ -2,7 +2,10 @@
 
 #include <stdint.h>
 
-struct linux_dirent64
+#define DIRENT_NAMELEN(X) ((X)->reclen - offsetof(linux_dirent64_t,name))
+
+typedef struct linux_dirent64_t linux_dirent64_t;
+struct linux_dirent64_t
 {
   uint64_t ino;
   int64_t  off;

libfuse/include/thread_pool.hpp

@@ -2,6 +2,7 @@
 
 #include "moodycamel/blockingconcurrentqueue.h"
 
+#include <algorithm>
 #include <atomic>
 #include <csignal>
 #include <cstring>
@@ -15,6 +16,7 @@
 
 #include <syslog.h>
 
+
 struct ThreadPoolTraits : public moodycamel::ConcurrentQueueDefaultTraits
 {
   static const int MAX_SEMA_SPINS = 1;
@@ -29,17 +31,20 @@ private:
 
 public:
   explicit
-  ThreadPool(std::size_t const thread_count_ = std::thread::hardware_concurrency(),
-             std::size_t const queue_depth_  = 1,
+  ThreadPool(unsigned const thread_count_    = std::thread::hardware_concurrency(),
+             unsigned const max_queue_depth_ = std::thread::hardware_concurrency(),
              std::string const name_         = {})
-    : _queue(queue_depth_,thread_count_,thread_count_),
+    : _queue(),
+      _queue_depth(0),
+      _max_queue_depth(std::max(thread_count_,max_queue_depth_)),
       _name(get_thread_name(name_))
   {
     syslog(LOG_DEBUG,
-           "threadpool: spawning %zu threads of queue depth %zu named '%s'",
+           "threadpool (%s): spawning %u threads w/ max queue depth %u%s",
+           _name.c_str(),
            thread_count_,
-           queue_depth_,
-           _name.c_str());
+           _max_queue_depth,
+           ((_max_queue_depth != max_queue_depth_) ? " (adjusted)" : ""));
 
     sigset_t oldset;
     sigset_t newset;
@@ -57,7 +62,8 @@ public:
         if(rv != 0)
           {
             syslog(LOG_WARNING,
-                   "threadpool: error spawning thread - %d (%s)",
+                   "threadpool (%s): error spawning thread - %d (%s)",
+                   _name.c_str(),
                    rv,
                    strerror(rv));
             continue;
@@ -78,9 +84,9 @@ public:
   ~ThreadPool()
   {
     syslog(LOG_DEBUG,
-           "threadpool: destroying %zu threads named '%s'",
-           _threads.size(),
-           _name.c_str());
+           "threadpool (%s): destroying %lu threads",
+           _name.c_str(),
+           _threads.size());
 
     auto func = []() { pthread_exit(NULL); };
     for(std::size_t i = 0; i < _threads.size(); i++)
@@ -114,6 +120,7 @@ private:
     ThreadPool *btp = static_cast<ThreadPool*>(arg_);
     ThreadPool::Func func;
     ThreadPool::Queue &q = btp->_queue;
+    std::atomic<unsigned> &queue_depth = btp->_queue_depth;
     moodycamel::ConsumerToken ctok(btp->_queue);
 
     while(true)
@@ -121,6 +128,8 @@ private:
         q.wait_dequeue(ctok,func);
 
         func();
+
+        queue_depth.fetch_sub(1,std::memory_order_release);
       }
 
     return NULL;
@@ -146,7 +155,8 @@ public:
     if(rv != 0)
       {
         syslog(LOG_WARNING,
-               "threadpool: error spawning thread - %d (%s)",
+               "threadpool (%s): error spawning thread - %d (%s)",
+               _name.c_str(),
                rv,
                strerror(rv));
         return -rv;
@@ -161,7 +171,7 @@ public:
     }
 
     syslog(LOG_DEBUG,
-           "threadpool: 1 thread added to pool '%s' named '%s'",
+           "threadpool (%s): 1 thread added named '%s'",
            _name.c_str(),
            name.c_str());
 
@@ -201,7 +211,7 @@ public:
       char name[16];
       pthread_getname_np(t,name,sizeof(name));
       syslog(LOG_DEBUG,
-             "threadpool: 1 thread removed from pool '%s' named '%s'",
+             "threadpool (%s): 1 thread removed named '%s'",
              _name.c_str(),
              name);
 
@@ -238,28 +248,32 @@ public:
   enqueue_work(moodycamel::ProducerToken  &ptok_,
                FuncType                  &&f_)
   {
-    timespec ts = {0,10};
-    while(true)
+    timespec ts = {0,1000};
+    for(unsigned i = 0; i < 1000000; i++)
       {
-        if(_queue.try_enqueue(ptok_,f_))
-          return;
+        if(_queue_depth.load(std::memory_order_acquire) < _max_queue_depth)
+          break;
         ::nanosleep(&ts,NULL);
-        ts.tv_nsec += 10;
       }
+
+    _queue.enqueue(ptok_,f_);
+    _queue_depth.fetch_add(1,std::memory_order_release);
   }
 
   template<typename FuncType>
   void
   enqueue_work(FuncType &&f_)
   {
-    timespec ts = {0,10};
-    while(true)
+    timespec ts = {0,1000};
+    for(unsigned i = 0; i < 1000000; i++)
       {
-        if(_queue.try_enqueue(f_))
-          return;
+        if(_queue_depth.load(std::memory_order_acquire) < _max_queue_depth)
+          break;
         ::nanosleep(&ts,NULL);
-        ts.tv_nsec += 10;
       }
+
+    _queue.enqueue(f_);
+    _queue_depth.fetch_add(1,std::memory_order_release);
   }
 
   template<typename FuncType>
@@ -272,21 +286,24 @@ public:
 
     auto promise = std::make_shared<Promise>();
     auto future  = promise->get_future();
+
     auto work = [=]()
     {
       auto rv = f_();
       promise->set_value(rv);
     };
 
-    timespec ts = {0,10};
-    while(true)
+    timespec ts = {0,1000};
+    for(unsigned i = 0; i < 1000000; i++)
       {
-        if(_queue.try_enqueue(work))
+        if(_queue_depth.load(std::memory_order_acquire) < _max_queue_depth)
           break;
         ::nanosleep(&ts,NULL);
-        ts.tv_nsec += 10;
       }
 
+    _queue.enqueue(work);
+    _queue_depth.fetch_add(1,std::memory_order_release);
+
     return future;
   }
 
@@ -307,6 +324,8 @@ public:
 
 private:
   Queue _queue;
+  std::atomic<unsigned> _queue_depth;
+  unsigned const        _max_queue_depth;
 
 private:
   std::string const      _name;

libfuse/lib/fuse_dirents.c

@@ -305,7 +305,7 @@ fuse_dirents_add_plus(fuse_dirents_t      *d_,
 
 int
 fuse_dirents_add_linux(fuse_dirents_t         *d_,
-                       const struct linux_dirent64 *dirent_,
+                       const linux_dirent64_t *dirent_,
                        const uint64_t          namelen_)
 {
   fuse_dirent_t *d;
@@ -337,7 +337,7 @@ fuse_dirents_add_linux(fuse_dirents_t              *d_,
 
 int
 fuse_dirents_add_linux_plus(fuse_dirents_t         *d_,
-                            const struct linux_dirent64 *dirent_,
+                            const linux_dirent64_t *dirent_,
                             const uint64_t          namelen_,
                             const fuse_entry_t     *entry_,
                             const struct stat      *st_)

libfuse/lib/fuse_loop.cpp

@@ -490,10 +490,13 @@ fuse_session_loop_mt(struct fuse_session *se_,
 
   if(process_thread_count > 0)
     process_tp = std::make_shared<ThreadPool>(process_thread_count,
-                                              process_thread_queue_depth,
+                                              (process_thread_count *
+                                               process_thread_queue_depth),
                                               "fuse.process");
 
-  read_tp = std::make_unique<ThreadPool>(read_thread_count,1,"fuse.read");
+  read_tp = std::make_unique<ThreadPool>(read_thread_count,
+                                         read_thread_count,
+                                         "fuse.read");
   if(process_tp)
     {
       for(auto i = 0; i < read_thread_count; i++)

src/fuse_readdir_cor.cpp

@@ -19,20 +19,24 @@
 #include "config.hpp"
 #include "dirinfo.hpp"
 #include "errno.hpp"
-#include "fs_closedir.hpp"
+#include "fs_close.hpp"
 #include "fs_devid.hpp"
+#include "fs_getdents64.hpp"
 #include "fs_inode.hpp"
-#include "fs_opendir.hpp"
+#include "fs_open.hpp"
 #include "fs_path.hpp"
 #include "fs_readdir.hpp"
 #include "hashset.hpp"
+#include "scope_guard.hpp"
 #include "ugid.hpp"
 
 #include "fuse_dirents.h"
+#include "linux_dirent64.h"
 
 
-FUSE::ReadDirCOR::ReadDirCOR(unsigned concurrency_)
-  : _tp(concurrency_,concurrency_,"readdir.cor")
+FUSE::ReadDirCOR::ReadDirCOR(unsigned concurrency_,
+                             unsigned max_queue_depth_)
+  : _tp(concurrency_,max_queue_depth_,"readdir.cor")
 {
 
 }
@@ -44,79 +48,98 @@ FUSE::ReadDirCOR::~ReadDirCOR()
 
 namespace l
 {
-  static
-  inline
-  uint64_t
-  dirent_exact_namelen(const struct dirent *d_)
+  struct Error
+  {
+  private:
+    int _err;
+
+  public:
+    Error()
+      : _err(ENOENT)
+    {
+    }
+
+    operator int()
     {
-#ifdef _D_EXACT_NAMLEN
-    return _D_EXACT_NAMLEN(d_);
-#elif defined _DIRENT_HAVE_D_NAMLEN
-    return d_->d_namlen;
-#else
-    return strlen(d_->d_name);
-#endif
+      return _err;
     }
 
+    Error&
+    operator=(int v_)
+    {
+      if(_err != 0)
+        _err = v_;
+
+      return *this;
+    }
+  };
+
   static
   inline
   int
   readdir(std::string     basepath_,
           HashSet        &names_,
-          std::mutex     &names_mutex_,
           fuse_dirents_t *buf_,
-          std::mutex     &dirents_mutex_)
+          std::mutex     &mutex_)
   {
     int rv;
-    int err;
-    DIR *dh;
+    int dfd;
     dev_t dev;
     std::string filepath;
 
-    dh = fs::opendir(basepath_);
-    if(dh == NULL)
-      return -errno;
+    dfd = fs::open_dir_ro(basepath_);
+    if(dfd == -1)
+      return errno;
+
+    DEFER{ fs::close(dfd); };
 
-    dev = fs::devid(dh);
+    dev = fs::devid(dfd);
 
     rv = 0;
-    err = 0;
-    for(struct dirent *de = fs::readdir(dh); de && !rv; de = fs::readdir(dh))
+    for(;;)
+      {
+        long nread;
+        char buf[32 * 1024];
+
+        nread = fs::getdents_64(dfd,buf,sizeof(buf));
+        if(nread == -1)
+          return errno;
+        if(nread == 0)
+          break;
+
+        linux_dirent64_t *d;
+        std::lock_guard<std::mutex> lk(mutex_);
+        for(long pos = 0; pos < nread; pos += d->reclen)
           {
             std::uint64_t namelen;
 
-        namelen = l::dirent_exact_namelen(de);
+            d = (linux_dirent64_t*)&buf[pos];
 
-        {
-          std::lock_guard<std::mutex> lk(names_mutex_);
-          rv = names_.put(de->d_name,namelen);
+            namelen = DIRENT_NAMELEN(d);
+
+            rv = names_.put(d->name,namelen);
             if(rv == 0)
               continue;
-        }
 
-        filepath  = fs::path::make(basepath_,de->d_name);
-        de->d_ino = fs::inode::calc(filepath,
-                                    DTTOIF(de->d_type),
+            filepath = fs::path::make(basepath_,d->name);
+            d->ino = fs::inode::calc(filepath,
+                                     DTTOIF(d->type),
                                      dev,
-                                    de->d_ino);
+                                     d->ino);
 
-        {
-          std::lock_guard<std::mutex> lk(dirents_mutex_);
-          rv = fuse_dirents_add(buf_,de,namelen);
-          if(rv == 0)
+            rv = fuse_dirents_add_linux(buf_,d,namelen);
+            if(rv >= 0)
               continue;
-        }
 
-        err = -ENOMEM;
+            return ENOMEM;
+          }
       }
 
-    fs::closedir(dh);
-
-    return err;
+    return 0;
   }
 
   static
-  std::vector<int>
+  int
   concurrent_readdir(ThreadPool           &tp_,
                      const Branches::CPtr &branches_,
                      const char           *dirname_,
@@ -125,11 +148,10 @@ namespace l
                      gid_t const           gid_)
   {
     HashSet names;
-    std::mutex names_mutex;
-    std::mutex dirents_mutex;
-    std::vector<int> rv;
+    std::mutex mutex;
     std::vector<std::future<int>> futures;
 
+    futures.reserve(branches_->size());
     for(auto const &branch : *branches_)
       {
         auto func = [&,dirname_,buf_,uid_,gid_]()
@@ -139,7 +161,7 @@ namespace l
 
           basepath = fs::path::make(branch.path,dirname_);
 
-          return l::readdir(basepath,names,names_mutex,buf_,dirents_mutex);
+          return l::readdir(basepath,names,buf_,mutex);
         };
 
         auto rv = tp_.enqueue_task(func);
@@ -147,26 +169,11 @@ namespace l
         futures.emplace_back(std::move(rv));
       }
 
+    Error error;
     for(auto &future : futures)
-      rv.push_back(future.get());
-
-    return rv;
-  }
-
-  static
-  int
-  calc_rv(std::vector<int> rvs_)
-  {
-    for(auto rv : rvs_)
-      {
-        if(rv == 0)
-          return 0;
-      }
-
-    if(rvs_.empty())
-      return -ENOENT;
+      error = future.get();
 
-    return rvs_[0];
+    return -error;
   }
 
   static
@@ -178,13 +185,9 @@ namespace l
           uid_t const           uid_,
           gid_t const           gid_)
   {
-    std::vector<int> rvs;
-
     fuse_dirents_reset(buf_);
 
-    rvs = l::concurrent_readdir(tp_,branches_,dirname_,buf_,uid_,gid_);
-
-    return l::calc_rv(rvs);
+    return l::concurrent_readdir(tp_,branches_,dirname_,buf_,uid_,gid_);
   }
 }
 

src/fuse_readdir_cor.hpp

@@ -29,7 +29,8 @@ namespace FUSE
   class ReadDirCOR final : public FUSE::ReadDirBase
   {
   public:
-    ReadDirCOR(unsigned concurrency);
+    ReadDirCOR(unsigned concurrency,
+               unsigned max_queue_depth);
     ~ReadDirCOR();
 
     int operator()(fuse_file_info_t const *ffi,

src/fuse_readdir_cosr.cpp

@@ -28,13 +28,15 @@
 #include "fs_readdir.hpp"
 #include "fs_stat.hpp"
 #include "hashset.hpp"
+#include "scope_guard.hpp"
 #include "ugid.hpp"
 
 #include "fuse_dirents.h"
 
 
-FUSE::ReadDirCOSR::ReadDirCOSR(unsigned concurrency_)
-  : _tp(concurrency_,concurrency_,"readdir.cosr")
+FUSE::ReadDirCOSR::ReadDirCOSR(unsigned concurrency_,
+                               unsigned max_queue_depth_)
+  : _tp(concurrency_,max_queue_depth_,"readdir.cosr")
 {
 
 }
@@ -46,8 +48,40 @@ FUSE::ReadDirCOSR::~ReadDirCOSR()
 
 namespace l
 {
+  struct DirRV
+  {
+    DIR *dir;
+    int  err;
+  };
+
+  struct Error
+  {
+  private:
+    int _err;
+
+  public:
+    Error()
+      : _err(ENOENT)
+    {
+
+    }
+
+    operator int()
+    {
+      return _err;
+    }
+
+    Error&
+    operator=(int const v_)
+    {
+      if(_err != 0)
+        _err = v_;
+
+      return *this;
+    }
+  };
+
   static
-  inline
   uint64_t
   dirent_exact_namelen(const struct dirent *d_)
   {
@@ -62,25 +96,31 @@ namespace l
 
   static
   inline
-  std::vector<std::future<DIR*>>
+  std::vector<std::future<DirRV>>
   opendir(ThreadPool           &tp_,
           const Branches::CPtr &branches_,
           char const           *dirname_,
           uid_t const           uid_,
           gid_t const           gid_)
   {
-    std::vector<std::future<DIR*>> futures;
+    std::vector<std::future<DirRV>> futures;
 
+    futures.reserve(branches_->size());
     for(auto const &branch : *branches_)
       {
         auto func = [&branch,dirname_,uid_,gid_]()
         {
+          DirRV rv;
           std::string basepath;
           ugid::Set const ugid(uid_,gid_);
 
           basepath = fs::path::make(branch.path,dirname_);
 
-          return fs::opendir(basepath);
+          errno  = 0;
+          rv.dir = fs::opendir(basepath);
+          rv.err = errno;
+
+          return rv;
         };
 
         auto rv = tp_.enqueue_task(func);
@@ -94,29 +134,31 @@ namespace l
   static
   inline
   int
-  readdir(std::vector<std::future<DIR*>> &dh_futures_,
+  readdir(std::vector<std::future<DirRV>> &dh_futures_,
           char const                      *dirname_,
           fuse_dirents_t                  *buf_)
   {
-    int err;
+    Error error;
     HashSet names;
     std::string fullpath;
 
-    err = 0;
     for(auto &dh_future : dh_futures_)
       {
         int rv;
-        DIR *dh;
         dev_t dev;
+        DirRV dirrv;
 
-        dh = dh_future.get();
-        if(dh == NULL)
+        dirrv = dh_future.get();
+        error = dirrv.err;
+        if(dirrv.dir == NULL)
           continue;
 
-        dev = fs::devid(dh);
+        DEFER { fs::closedir(dirrv.dir); };
+
+        dev = fs::devid(dirrv.dir);
 
         rv = 0;
-        for(struct dirent *de = fs::readdir(dh); de && !rv; de = fs::readdir(dh))
+        for(dirent *de = fs::readdir(dirrv.dir); de && !rv; de = fs::readdir(dirrv.dir))
           {
             std::uint64_t namelen;
 
@@ -136,13 +178,11 @@ namespace l
             if(rv == 0)
               continue;
 
-            err = -ENOMEM;
+            error = ENOMEM;
           }
-
-        fs::closedir(dh);
       }
 
-    return err;
+    return -error;
   }
 
   static
@@ -156,12 +196,12 @@ namespace l
           gid_t const           gid_)
   {
     int rv;
-    std::vector<std::future<DIR*>> dh_futures;
+    std::vector<std::future<DirRV>> futures;
 
     fuse_dirents_reset(buf_);
 
-    dh_futures = l::opendir(tp_,branches_,dirname_,uid_,gid_);
-    rv         = l::readdir(dh_futures,dirname_,buf_);
+    futures = l::opendir(tp_,branches_,dirname_,uid_,gid_);
+    rv      = l::readdir(futures,dirname_,buf_);
 
     return rv;
   }

src/fuse_readdir_cosr.hpp

@@ -28,7 +28,8 @@ namespace FUSE
   class ReadDirCOSR final : public FUSE::ReadDirBase
   {
   public:
-    ReadDirCOSR(unsigned concurrency);
+    ReadDirCOSR(unsigned concurrency,
+                unsigned max_queue_depth);
     ~ReadDirCOSR();
 
     int operator()(fuse_file_info_t const *ffi,

src/fuse_readdir_factory.cpp

@@ -28,6 +28,7 @@
 #include <cstdlib>
 #include <set>
 
+#define DEFAULT_MAX_QUEUE_DEPTH 3
 
 namespace l
 {
@@ -35,13 +36,20 @@ namespace l
   void
   read_cfg(std::string const  str_,
            std::string       &type_,
-           int               &concurrency_)
+           unsigned          &concurrency_,
+           unsigned          &max_queue_depth_)
   {
     char type[16];
     int concurrency;
+    int max_queue_depth;
 
     concurrency = 0;
-    std::sscanf(str_.c_str(),"%15[a-z]:%d",type,&concurrency);
+    max_queue_depth = 0;
+    std::sscanf(str_.c_str(),
+                "%15[a-z]:%d:%d",
+                type,
+                &concurrency,
+                &max_queue_depth);
 
     if(concurrency == 0)
       concurrency = std::thread::hardware_concurrency();
@@ -51,22 +59,29 @@ namespace l
     if(concurrency == 0)
       concurrency = 1;
 
+    if(max_queue_depth == 0)
+      max_queue_depth = DEFAULT_MAX_QUEUE_DEPTH;
+
+    max_queue_depth *= concurrency;
+
     type_            = type;
     concurrency_     = concurrency;
+    max_queue_depth_ = max_queue_depth;
   }
 }
 
 bool
 FUSE::ReadDirFactory::valid(std::string const str_)
 {
-  int concurrency;
+  unsigned concurrency;
+  unsigned max_queue_depth;
   std::string type;
   static const std::set<std::string> types =
     {
       "seq", "cosr", "cor"
     };
 
-  l::read_cfg(str_,type,concurrency);
+  l::read_cfg(str_,type,concurrency,max_queue_depth);
 
   if(types.find(type) == types.end())
     return false;
@@ -79,20 +94,21 @@ FUSE::ReadDirFactory::valid(std::string const str_)
 std::shared_ptr<FUSE::ReadDirBase>
 FUSE::ReadDirFactory::make(std::string const str_)
 {
-  int concurrency;
+  unsigned concurrency;
+  unsigned max_queue_depth;
   std::string type;
 
   if(!valid(str_))
     return {};
 
-  l::read_cfg(str_,type,concurrency);
+  l::read_cfg(str_,type,concurrency,max_queue_depth);
 
   if(type == "seq")
     return std::make_shared<FUSE::ReadDirSeq>();
   if(type == "cosr")
-    return std::make_shared<FUSE::ReadDirCOSR>(concurrency);
+    return std::make_shared<FUSE::ReadDirCOSR>(concurrency,max_queue_depth);
   if(type == "cor")
-    return std::make_shared<FUSE::ReadDirCOR>(concurrency);
+    return std::make_shared<FUSE::ReadDirCOR>(concurrency,max_queue_depth);
 
   return {};
 }

src/fuse_readdir_linux.cpp

@@ -1,135 +0,0 @@
-/*
-  Copyright (c) 2020, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#include "branches.hpp"
-#include "errno.hpp"
-#include "fs_close.hpp"
-#include "fs_devid.hpp"
-#include "fs_getdents64.hpp"
-#include "fs_inode.hpp"
-#include "fs_open.hpp"
-#include "fs_path.hpp"
-#include "fs_stat.hpp"
-#include "hashset.hpp"
-#include "linux_dirent64.h"
-#include "mempools.hpp"
-
-#include "fuse.h"
-#include "fuse_dirents.h"
-
-#include <string>
-#include <vector>
-
-#include <stddef.h>
-
-using std::string;
-using std::vector;
-
-namespace l
-{
-  static
-  int
-  close_free_ret_enomem(int   fd_,
-                        void *buf_)
-  {
-    fs::close(fd_);
-    g_DENTS_BUF_POOL.free(buf_);
-    return -ENOMEM;
-  }
-
-  static
-  int
-  readdir(const Branches::CPtr &branches_,
-          const char           *dirname_,
-          fuse_dirents_t       *buf_)
-  {
-    int rv;
-    dev_t dev;
-    char *buf;
-    HashSet names;
-    string basepath;
-    string fullpath;
-    uint64_t namelen;
-    struct linux_dirent64 *d;
-
-    fuse_dirents_reset(buf_);
-
-    buf = (char*)g_DENTS_BUF_POOL.alloc();
-    if(buf == NULL)
-      return -ENOMEM;
-
-    for(const auto &branch : *branches_)
-      {
-        int dirfd;
-        int64_t nread;
-
-        basepath = fs::path::make(branch.path,dirname_);
-
-        dirfd = fs::open_dir_ro(basepath);
-        if(dirfd == -1)
-          continue;
-
-        dev = fs::devid(dirfd);
-
-        for(;;)
-          {
-            nread = fs::getdents_64(dirfd,buf,g_DENTS_BUF_POOL.size());
-            if(nread == -1)
-              break;
-            if(nread == 0)
-              break;
-
-            for(int64_t pos = 0; pos < nread; pos += d->reclen)
-              {
-                d = (struct linux_dirent64*)(buf + pos);
-                namelen = strlen(d->name);
-
-                rv = names.put(d->name,namelen);
-                if(rv == 0)
-                  continue;
-
-                fullpath = fs::path::make(dirname_,d->name);
-                d->ino = fs::inode::calc(fullpath.c_str(),
-                                         fullpath.size(),
-                                         DTTOIF(d->type),
-                                         dev,
-                                         d->ino);
-
-                rv = fuse_dirents_add_linux(buf_,d,namelen);
-                if(rv)
-                  return close_free_ret_enomem(dirfd,buf);
-              }
-          }
-
-        fs::close(dirfd);
-      }
-
-    g_DENTS_BUF_POOL.free(buf);
-
-    return 0;
-  }
-}
-
-namespace FUSE
-{
-  int
-  readdir_linux(const Branches::CPtr &branches_,
-                const char           *dirname_,
-                fuse_dirents_t       *buf_)
-  {
-    return l::readdir(branches_,dirname_,buf_);
-  }
-}

src/fuse_readdir_linux.hpp

@@ -1,34 +0,0 @@
-/*
-  ISC License
-
-  Copyright (c) 2020, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#pragma once
-
-#include "branches.hpp"
-
-#include "fuse.h"
-
-#include <cstdint>
-
-
-namespace FUSE
-{
-  int
-  readdir_linux(const Branches::CPtr &branches,
-                const char           *dirname,
-                fuse_dirents_t       *buf);
-}

src/fuse_readdir_plus.cpp

@@ -1,7 +1,7 @@
 /*
   ISC License
 
-  Copyright (c) 2020, Antonio SJ Musumeci <trapexit@spawn.link>
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
 
   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
@@ -16,17 +16,14 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
-#include "errno.hpp"
+#include "fuse_readdir_plus.hpp"
 
-#include "fuse.h"
+#include <errno.h>
 
 
-namespace FUSE
-{
-  int
-  readdir_plus(const fuse_file_info_t *ffi_,
+int
+FUSE::readdir_plus(const fuse_file_info_t *ffi_,
                    fuse_dirents_t         *buf_)
-  {
+{
   return -ENOTSUP;
-  }
 }

src/fuse_readdir_plus.hpp

@@ -1,5 +1,5 @@
 /*
-  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
 
   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
@@ -21,7 +21,6 @@
 
 namespace FUSE
 {
-  int
-  readdir_plus(const fuse_file_info_t *ffi,
+  int readdir_plus(fuse_file_info_t const *ffi,
                    fuse_dirents_t         *buf);
 }

src/fuse_readdir_plus_linux.cpp

@@ -1,151 +0,0 @@
-/*
-  Copyright (c) 2019, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#include "branches.hpp"
-#include "errno.hpp"
-#include "fs_close.hpp"
-#include "fs_devid.hpp"
-#include "fs_fstatat.hpp"
-#include "fs_getdents64.hpp"
-#include "fs_inode.hpp"
-#include "fs_open.hpp"
-#include "fs_path.hpp"
-#include "fs_stat.hpp"
-#include "hashset.hpp"
-#include "linux_dirent64.h"
-#include "mempools.hpp"
-
-#include "fuse.h"
-#include "fuse_dirents.h"
-
-#include <string>
-#include <vector>
-
-#include <stddef.h>
-
-using std::string;
-using std::vector;
-
-namespace l
-{
-  static
-  int
-  close_free_ret_enomem(int   fd_,
-                        void *buf_)
-  {
-    fs::close(fd_);
-    g_DENTS_BUF_POOL.free(buf_);
-    return -ENOMEM;
-  }
-
-  static
-  int
-  readdir_plus(const Branches::CPtr &branches_,
-               const char           *dirname_,
-               const uint64_t        entry_timeout_,
-               const uint64_t        attr_timeout_,
-               fuse_dirents_t       *buf_)
-  {
-    int rv;
-    dev_t dev;
-    char *buf;
-    HashSet names;
-    string basepath;
-    string fullpath;
-    uint64_t namelen;
-    struct stat st;
-    fuse_entry_t entry;
-    struct linux_dirent64 *d;
-
-    fuse_dirents_reset(buf_);
-
-    buf = (char*)g_DENTS_BUF_POOL.alloc();
-
-    entry.nodeid           = 0;
-    entry.generation       = 0;
-    entry.entry_valid      = entry_timeout_;
-    entry.attr_valid       = attr_timeout_;
-    entry.entry_valid_nsec = 0;
-    entry.attr_valid_nsec  = 0;
-    for(auto &branch : *branches_)
-      {
-        int dirfd;
-        int64_t nread;
-
-        basepath = fs::path::make(branch.path,dirname_);
-
-        dirfd = fs::open_dir_ro(basepath);
-        if(dirfd == -1)
-          continue;
-        dev = fs::devid(dirfd);
-
-        for(;;)
-          {
-            nread = fs::getdents_64(dirfd,buf,g_DENTS_BUF_POOL.size());
-            if(nread == -1)
-              break;
-            if(nread == 0)
-              break;
-
-            for(int64_t pos = 0; pos < nread; pos += d->reclen)
-              {
-                d = (struct linux_dirent64*)(buf + pos);
-                namelen = (strlen(d->name) + 1);
-
-                rv = names.put(d->name,namelen);
-                if(rv == 0)
-                  continue;
-
-                rv = fs::fstatat_nofollow(dirfd,d->name,&st);
-                if(rv == -1)
-                  {
-                    memset(&st,0,sizeof(st));
-                    st.st_ino  = d->ino;
-                    st.st_dev  = dev;
-                    st.st_mode = DTTOIF(d->type);
-                  }
-
-                fullpath = fs::path::make(dirname_,d->name);
-                fs::inode::calc(fullpath,&st);
-                d->ino = st.st_ino;
-
-                rv = fuse_dirents_add_linux_plus(buf_,d,namelen,&entry,&st);
-                if(rv)
-                  return close_free_ret_enomem(dirfd,buf);
-              }
-          }
-
-        fs::close(dirfd);
-      }
-
-    g_DENTS_BUF_POOL.free(buf);
-
-    return 0;
-  }
-}
-
-namespace FUSE
-{
-  int
-  readdir_plus_linux(const Branches::CPtr &branches_,
-                     const char           *dirname_,
-                     const uint64_t        entry_timeout_,
-                     const uint64_t        attr_timeout_,
-                     fuse_dirents_t       *buf_)
-  {
-    return l::readdir_plus(branches_,dirname_,entry_timeout_,attr_timeout_,buf_);
-  }
-}

src/fuse_readdir_plus_linux.hpp

@@ -1,36 +0,0 @@
-/*
-  ISC License
-
-  Copyright (c) 2020, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#pragma once
-
-#include "branches.hpp"
-
-#include "fuse.h"
-
-#include <cstdint>
-
-
-namespace FUSE
-{
-  int
-  readdir_plus_linux(const Branches::CPtr &branches,
-                     const char           *dirname,
-                     const uint64_t        entry_timeout,
-                     const uint64_t        attr_timeout,
-                     fuse_dirents_t       *buf);
-}

src/fuse_readdir_plus_posix.cpp

@@ -1,142 +0,0 @@
-/*
-  Copyright (c) 2019, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#define _DEFAULT_SOURCE
-
-#include "branches.hpp"
-#include "errno.hpp"
-#include "fs_closedir.hpp"
-#include "fs_devid.hpp"
-#include "fs_dirfd.hpp"
-#include "fs_fstatat.hpp"
-#include "fs_inode.hpp"
-#include "fs_opendir.hpp"
-#include "fs_path.hpp"
-#include "fs_readdir.hpp"
-#include "fs_stat.hpp"
-#include "hashset.hpp"
-
-#include "fuse.h"
-#include "fuse_dirents.h"
-
-#include <string>
-#include <vector>
-
-#include <dirent.h>
-
-using std::string;
-using std::vector;
-
-namespace l
-{
-  static
-  uint64_t
-  dirent_exact_namelen(const struct dirent *d_)
-  {
-#ifdef _D_EXACT_NAMLEN
-    return _D_EXACT_NAMLEN(d_);
-#elif defined _DIRENT_HAVE_D_NAMLEN
-    return d_->d_namlen;
-#else
-    return strlen(d_->d_name);
-#endif
-  }
-
-  static
-  int
-  readdir_plus(const Branches::CPtr &branches_,
-               const char           *dirname_,
-               const uint64_t        entry_timeout_,
-               const uint64_t        attr_timeout_,
-               fuse_dirents_t       *buf_)
-  {
-    dev_t dev;
-    HashSet names;
-    string basepath;
-    string fullpath;
-    struct stat st;
-    uint64_t namelen;
-    fuse_entry_t entry;
-
-    fuse_dirents_reset(buf_);
-
-    entry.nodeid           = 0;
-    entry.generation       = 0;
-    entry.entry_valid      = entry_timeout_;
-    entry.attr_valid       = attr_timeout_;
-    entry.entry_valid_nsec = 0;
-    entry.attr_valid_nsec  = 0;
-    for(auto &branch : *branches_)
-      {
-        int rv;
-        int dirfd;
-        DIR *dh;
-
-        basepath = fs::path::make(branch.path,dirname_);
-
-        dh = fs::opendir(basepath);
-        if(!dh)
-          continue;
-
-        dirfd = fs::dirfd(dh);
-        dev   = fs::devid(dirfd);
-
-        rv = 0;
-        for(struct dirent *de = fs::readdir(dh); de && !rv; de = fs::readdir(dh))
-          {
-            namelen = l::dirent_exact_namelen(de);
-
-            rv = names.put(de->d_name,namelen);
-            if(rv == 0)
-              continue;
-
-            rv = fs::fstatat_nofollow(dirfd,de->d_name,&st);
-            if(rv == -1)
-              {
-                memset(&st,0,sizeof(st));
-                st.st_ino  = de->d_ino;
-                st.st_dev  = dev;
-                st.st_mode = DTTOIF(de->d_type);
-              }
-
-            fullpath = fs::path::make(dirname_,de->d_name);
-            fs::inode::calc(fullpath,&st);
-            de->d_ino = st.st_ino;
-
-            rv = fuse_dirents_add_plus(buf_,de,namelen,&entry,&st);
-            if(rv)
-              return (fs::closedir(dh),-ENOMEM);
-          }
-
-        fs::closedir(dh);
-      }
-
-    return 0;
-  }
-}
-
-namespace FUSE
-{
-  int
-  readdir_plus_posix(const Branches::CPtr &branches_,
-                     const char           *dirname_,
-                     const uint64_t        entry_timeout_,
-                     const uint64_t        attr_timeout_,
-                     fuse_dirents_t       *buf_)
-  {
-    return l::readdir_plus(branches_,dirname_,entry_timeout_,attr_timeout_,buf_);
-  }
-}

src/fuse_readdir_plus_posix.hpp

@@ -1,36 +0,0 @@
-/*
-  ISC License
-
-  Copyright (c) 2020, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#pragma once
-
-#include "branches.hpp"
-
-#include "fuse.h"
-
-#include <cstdint>
-
-
-namespace FUSE
-{
-  int
-  readdir_plus_posix(const Branches::CPtr &branches,
-                     const char           *dirname,
-                     const uint64_t        entry_timeout,
-                     const uint64_t        attr_timeout,
-                     fuse_dirents_t       *buf);
-}

src/fuse_readdir_seq.cpp

@@ -31,17 +31,44 @@
 #include "fs_readdir.hpp"
 #include "fs_stat.hpp"
 #include "hashset.hpp"
+#include "scope_guard.hpp"
 #include "ugid.hpp"
 
 #include "fuse.h"
 #include "fuse_dirents.h"
 
 #include <string>
-#include <vector>
 
 
 namespace l
 {
+  struct Error
+  {
+  private:
+    int _err;
+
+  public:
+    Error()
+      : _err(ENOENT)
+    {
+
+    }
+
+    operator int()
+    {
+      return _err;
+    }
+
+    Error&
+    operator=(int v_)
+    {
+      if(_err != 0)
+        _err = v_;
+
+      return *this;
+    }
+  };
+
   static
   uint64_t
   dirent_exact_namelen(const struct dirent *d_)
@@ -61,13 +88,14 @@ namespace l
           const char           *dirname_,
           fuse_dirents_t       *buf_)
   {
+    Error error;
     HashSet names;
     std::string basepath;
     std::string fullpath;
 
     fuse_dirents_reset(buf_);
 
-    for(const auto &branch : *branches_)
+    for(auto const &branch : *branches_)
       {
         int rv;
         DIR *dh;
@@ -75,14 +103,18 @@ namespace l
 
         basepath = fs::path::make(branch.path,dirname_);
 
+        errno = 0;
         dh = fs::opendir(basepath);
+        error = errno;
         if(!dh)
           continue;
 
+        DEFER{ fs::closedir(dh); };
+
         dev = fs::devid(dh);
 
         rv = 0;
-        for(struct dirent *de = fs::readdir(dh); de && !rv; de = fs::readdir(dh))
+        for(dirent *de = fs::readdir(dh); de && !rv; de = fs::readdir(dh))
           {
             std::uint64_t namelen;
 
@@ -100,13 +132,11 @@ namespace l
 
             rv = fuse_dirents_add(buf_,de,namelen);
             if(rv)
-              return (fs::closedir(dh),-ENOMEM);
+              return -ENOMEM;
           }
-
-        fs::closedir(dh);
       }
 
-    return 0;
+    return -error;
   }
 }
 

src/scope_guard.hpp

@@ -0,0 +1,369 @@
+//   _____                         _____                     _    _____
+//  / ____|                       / ____|                   | |  / ____|_     _
+// | (___   ___ ___  _ __   ___  | |  __ _   _  __ _ _ __ __| | | |   _| |_ _| |_
+//  \___ \ / __/ _ \| '_ \ / _ \ | | |_ | | | |/ _` | '__/ _` | | |  |_   _|_   _|
+//  ____) | (_| (_) | |_) |  __/ | |__| | |_| | (_| | | | (_| | | |____|_|   |_|
+// |_____/ \___\___/| .__/ \___|  \_____|\__,_|\__,_|_|  \__,_|  \_____|
+//                  | | https://github.com/Neargye/scope_guard
+//                  |_| version 0.9.1
+//
+// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018 - 2021 Daniil Goncharov <neargye@gmail.com>.
+//
+// Permission is hereby  granted, free of charge, to any  person obtaining a copy
+// of this software and associated  documentation files (the "Software"), to deal
+// in the Software  without restriction, including without  limitation the rights
+// to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+// copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+// IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+// FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+// AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+// LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#ifndef NEARGYE_SCOPE_GUARD_HPP
+#define NEARGYE_SCOPE_GUARD_HPP
+
+#define SCOPE_GUARD_VERSION_MAJOR 0
+#define SCOPE_GUARD_VERSION_MINOR 9
+#define SCOPE_GUARD_VERSION_PATCH 1
+
+#include <type_traits>
+#if (defined(_MSC_VER) && _MSC_VER >= 1900) || ((defined(__clang__) || defined(__GNUC__)) && __cplusplus >= 201700L)
+#include <exception>
+#endif
+
+// scope_guard throwable settings:
+// SCOPE_GUARD_NO_THROW_CONSTRUCTIBLE requires nothrow constructible action.
+// SCOPE_GUARD_MAY_THROW_ACTION action may throw exceptions.
+// SCOPE_GUARD_NO_THROW_ACTION requires noexcept action.
+// SCOPE_GUARD_SUPPRESS_THROW_ACTION exceptions during action will be suppressed.
+// SCOPE_GUARD_CATCH_HANDLER exceptions handler. If SCOPE_GUARD_SUPPRESS_THROW_ACTIONS is not defined, it will do nothing.
+
+#if !defined(SCOPE_GUARD_MAY_THROW_ACTION) && !defined(SCOPE_GUARD_NO_THROW_ACTION) && !defined(SCOPE_GUARD_SUPPRESS_THROW_ACTION)
+#  define SCOPE_GUARD_MAY_THROW_ACTION
+#elif (defined(SCOPE_GUARD_MAY_THROW_ACTION) + defined(SCOPE_GUARD_NO_THROW_ACTION) + defined(SCOPE_GUARD_SUPPRESS_THROW_ACTION)) > 1
+#  error Only one of SCOPE_GUARD_MAY_THROW_ACTION and SCOPE_GUARD_NO_THROW_ACTION and SCOPE_GUARD_SUPPRESS_THROW_ACTION may be defined.
+#endif
+
+#if !defined(SCOPE_GUARD_CATCH_HANDLER)
+#  define SCOPE_GUARD_CATCH_HANDLER /* Suppress exception.*/
+#endif
+
+namespace scope_guard {
+
+namespace detail {
+
+#if defined(SCOPE_GUARD_SUPPRESS_THROW_ACTION) && (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || (_HAS_EXCEPTIONS))
+#  define NEARGYE_NOEXCEPT(...) noexcept
+#  define NEARGYE_TRY           try {
+#  define NEARGYE_CATCH         } catch (...) { SCOPE_GUARD_CATCH_HANDLER }
+#else
+#  define NEARGYE_NOEXCEPT(...) noexcept(__VA_ARGS__)
+#  define NEARGYE_TRY
+#  define NEARGYE_CATCH
+#endif
+
+#define NEARGYE_MOV(...) static_cast<typename std::remove_reference<decltype(__VA_ARGS__)>::type&&>(__VA_ARGS__)
+#define NEARGYE_FWD(...) static_cast<decltype(__VA_ARGS__)&&>(__VA_ARGS__)
+
+// NEARGYE_NODISCARD encourages the compiler to issue a warning if the return value is discarded.
+#if !defined(NEARGYE_NODISCARD)
+#  if defined(__clang__)
+#    if (__clang_major__ * 10 + __clang_minor__) >= 39 && __cplusplus >= 201703L
+#      define NEARGYE_NODISCARD [[nodiscard]]
+#    else
+#      define NEARGYE_NODISCARD __attribute__((__warn_unused_result__))
+#    endif
+#  elif defined(__GNUC__)
+#    if __GNUC__ >= 7 && __cplusplus >= 201703L
+#      define NEARGYE_NODISCARD [[nodiscard]]
+#    else
+#      define NEARGYE_NODISCARD __attribute__((__warn_unused_result__))
+#    endif
+#  elif defined(_MSC_VER)
+#    if _MSC_VER >= 1911 && defined(_MSVC_LANG) && _MSVC_LANG >= 201703L
+#      define NEARGYE_NODISCARD [[nodiscard]]
+#    elif defined(_Check_return_)
+#      define NEARGYE_NODISCARD _Check_return_
+#    else
+#      define NEARGYE_NODISCARD
+#    endif
+#  else
+#    define NEARGYE_NODISCARD
+#  endif
+#endif
+
+#if defined(_MSC_VER) && _MSC_VER < 1900
+inline int uncaught_exceptions() noexcept {
+  return *(reinterpret_cast<int*>(static_cast<char*>(static_cast<void*>(_getptd())) + (sizeof(void*) == 8 ? 0x100 : 0x90)));
+}
+#elif (defined(__clang__) || defined(__GNUC__)) && __cplusplus < 201700L
+struct __cxa_eh_globals;
+extern "C" __cxa_eh_globals* __cxa_get_globals() noexcept;
+inline int uncaught_exceptions() noexcept {
+  return static_cast<int>(*(reinterpret_cast<unsigned int*>(static_cast<char*>(static_cast<void*>(__cxa_get_globals())) + sizeof(void*))));
+}
+#else
+inline int uncaught_exceptions() noexcept {
+  return std::uncaught_exceptions();
+}
+#endif
+
+class on_exit_policy {
+  bool execute_;
+
+ public:
+  explicit on_exit_policy(bool execute) noexcept : execute_{execute} {}
+
+  void dismiss() noexcept {
+    execute_ = false;
+  }
+
+  bool should_execute() const noexcept {
+    return execute_;
+  }
+};
+
+class on_fail_policy {
+  int ec_;
+
+ public:
+  explicit on_fail_policy(bool execute) noexcept : ec_{execute ? uncaught_exceptions() : -1} {}
+
+  void dismiss() noexcept {
+    ec_ = -1;
+  }
+
+  bool should_execute() const noexcept {
+    return ec_ != -1 && ec_ < uncaught_exceptions();
+  }
+};
+
+class on_success_policy {
+  int ec_;
+
+ public:
+  explicit on_success_policy(bool execute) noexcept : ec_{execute ? uncaught_exceptions() : -1} {}
+
+  void dismiss() noexcept {
+    ec_ = -1;
+  }
+
+  bool should_execute() const noexcept {
+    return ec_ != -1 && ec_ >= uncaught_exceptions();
+  }
+};
+
+template <typename T, typename = void>
+struct is_noarg_returns_void_action
+    : std::false_type {};
+
+template <typename T>
+struct is_noarg_returns_void_action<T, decltype((std::declval<T>())())>
+    : std::true_type {};
+
+template <typename T, bool = is_noarg_returns_void_action<T>::value>
+struct is_nothrow_invocable_action
+    : std::false_type {};
+
+template <typename T>
+struct is_nothrow_invocable_action<T, true>
+    : std::integral_constant<bool, noexcept((std::declval<T>())())> {};
+
+template <typename F, typename P>
+class scope_guard {
+  using A = typename std::decay<F>::type;
+
+  static_assert(is_noarg_returns_void_action<A>::value,
+                "scope_guard requires no-argument action, that returns void.");
+  static_assert(std::is_same<P, on_exit_policy>::value || std::is_same<P, on_fail_policy>::value || std::is_same<P, on_success_policy>::value,
+                "scope_guard requires on_exit_policy, on_fail_policy or on_success_policy.");
+#if defined(SCOPE_GUARD_NO_THROW_ACTION)
+    static_assert(is_nothrow_invocable_action<A>::value,
+                  "scope_guard requires noexcept invocable action.");
+#endif
+#if defined(SCOPE_GUARD_NO_THROW_CONSTRUCTIBLE)
+  static_assert(std::is_nothrow_move_constructible<A>::value,
+                "scope_guard requires nothrow constructible action.");
+#endif
+
+  P policy_;
+  A action_;
+
+  void* operator new(std::size_t) = delete;
+  void operator delete(void*) = delete;
+
+ public:
+  scope_guard() = delete;
+  scope_guard(const scope_guard&) = delete;
+  scope_guard& operator=(const scope_guard&) = delete;
+  scope_guard& operator=(scope_guard&&) = delete;
+
+  scope_guard(scope_guard&& other) noexcept(std::is_nothrow_move_constructible<A>::value)
+      : policy_{false},
+        action_{NEARGYE_MOV(other.action_)} {
+    policy_ = NEARGYE_MOV(other.policy_);
+    other.policy_.dismiss();
+  }
+
+  scope_guard(const A& action) = delete;
+  scope_guard(A& action) = delete;
+
+  explicit scope_guard(A&& action) noexcept(std::is_nothrow_move_constructible<A>::value)
+      : policy_{true},
+        action_{NEARGYE_MOV(action)} {}
+
+  void dismiss() noexcept {
+    policy_.dismiss();
+  }
+
+  ~scope_guard() NEARGYE_NOEXCEPT(is_nothrow_invocable_action<A>::value) {
+    if (policy_.should_execute()) {
+      NEARGYE_TRY
+        action_();
+      NEARGYE_CATCH
+    }
+  }
+};
+
+template <typename F>
+using scope_exit = scope_guard<F, on_exit_policy>;
+
+template <typename F, typename std::enable_if<is_noarg_returns_void_action<F>::value, int>::type = 0>
+NEARGYE_NODISCARD scope_exit<F> make_scope_exit(F&& action) noexcept(noexcept(scope_exit<F>{NEARGYE_FWD(action)})) {
+  return scope_exit<F>{NEARGYE_FWD(action)};
+}
+
+template <typename F>
+using scope_fail = scope_guard<F, on_fail_policy>;
+
+template <typename F, typename std::enable_if<is_noarg_returns_void_action<F>::value, int>::type = 0>
+NEARGYE_NODISCARD scope_fail<F> make_scope_fail(F&& action) noexcept(noexcept(scope_fail<F>{NEARGYE_FWD(action)})) {
+  return scope_fail<F>{NEARGYE_FWD(action)};
+}
+
+template <typename F>
+using scope_success = scope_guard<F, on_success_policy>;
+
+template <typename F, typename std::enable_if<is_noarg_returns_void_action<F>::value, int>::type = 0>
+NEARGYE_NODISCARD scope_success<F> make_scope_success(F&& action) noexcept(noexcept(scope_success<F>{NEARGYE_FWD(action)})) {
+  return scope_success<F>{NEARGYE_FWD(action)};
+}
+
+struct scope_exit_tag {};
+
+template <typename F, typename std::enable_if<is_noarg_returns_void_action<F>::value, int>::type = 0>
+scope_exit<F> operator<<(scope_exit_tag, F&& action) noexcept(noexcept(scope_exit<F>{NEARGYE_FWD(action)})) {
+  return scope_exit<F>{NEARGYE_FWD(action)};
+}
+
+struct scope_fail_tag {};
+
+template <typename F, typename std::enable_if<is_noarg_returns_void_action<F>::value, int>::type = 0>
+scope_fail<F> operator<<(scope_fail_tag, F&& action) noexcept(noexcept(scope_fail<F>{NEARGYE_FWD(action)})) {
+  return scope_fail<F>{NEARGYE_FWD(action)};
+}
+
+struct scope_success_tag {};
+
+template <typename F, typename std::enable_if<is_noarg_returns_void_action<F>::value, int>::type = 0>
+scope_success<F> operator<<(scope_success_tag, F&& action) noexcept(noexcept(scope_success<F>{NEARGYE_FWD(action)})) {
+  return scope_success<F>{NEARGYE_FWD(action)};
+}
+
+#undef NEARGYE_MOV
+#undef NEARGYE_FWD
+#undef NEARGYE_NOEXCEPT
+#undef NEARGYE_TRY
+#undef NEARGYE_CATCH
+#undef NEARGYE_NODISCARD
+
+} // namespace scope_guard::detail
+
+using detail::make_scope_exit;
+using detail::make_scope_fail;
+using detail::make_scope_success;
+
+} // namespace scope_guard
+
+// NEARGYE_MAYBE_UNUSED suppresses compiler warnings on unused entities, if any.
+#if !defined(NEARGYE_MAYBE_UNUSED)
+#  if defined(__clang__)
+#    if (__clang_major__ * 10 + __clang_minor__) >= 39 && __cplusplus >= 201703L
+#      define NEARGYE_MAYBE_UNUSED [[maybe_unused]]
+#    else
+#      define NEARGYE_MAYBE_UNUSED __attribute__((__unused__))
+#    endif
+#  elif defined(__GNUC__)
+#    if __GNUC__ >= 7 && __cplusplus >= 201703L
+#      define NEARGYE_MAYBE_UNUSED [[maybe_unused]]
+#    else
+#      define NEARGYE_MAYBE_UNUSED __attribute__((__unused__))
+#    endif
+#  elif defined(_MSC_VER)
+#    if _MSC_VER >= 1911 && defined(_MSVC_LANG) && _MSVC_LANG >= 201703L
+#      define NEARGYE_MAYBE_UNUSED [[maybe_unused]]
+#    else
+#      define NEARGYE_MAYBE_UNUSED __pragma(warning(suppress : 4100 4101 4189))
+#    endif
+#  else
+#    define NEARGYE_MAYBE_UNUSED
+#  endif
+#endif
+
+#if !defined(NEARGYE_STR_CONCAT)
+#  define NEARGYE_STR_CONCAT_(s1, s2) s1##s2
+#  define NEARGYE_STR_CONCAT(s1, s2)  NEARGYE_STR_CONCAT_(s1, s2)
+#endif
+
+#if !defined(NEARGYE_COUNTER)
+#  if defined(__COUNTER__)
+#    define NEARGYE_COUNTER __COUNTER__
+#  elif defined(__LINE__)
+#    define NEARGYE_COUNTER __LINE__
+#  endif
+#endif
+
+#if defined(SCOPE_GUARD_NO_THROW_ACTION)
+#  define NEARGYE_MAKE_SCOPE_GUARD_ACTION [&]() noexcept -> void
+#else
+#  define NEARGYE_MAKE_SCOPE_GUARD_ACTION [&]() -> void
+#endif
+
+#define NEARGYE_MAKE_SCOPE_EXIT    ::scope_guard::detail::scope_exit_tag{}    << NEARGYE_MAKE_SCOPE_GUARD_ACTION
+#define NEARGYE_MAKE_SCOPE_FAIL    ::scope_guard::detail::scope_fail_tag{}    << NEARGYE_MAKE_SCOPE_GUARD_ACTION
+#define NEARGYE_MAKE_SCOPE_SUCCESS ::scope_guard::detail::scope_success_tag{} << NEARGYE_MAKE_SCOPE_GUARD_ACTION
+
+#define NEARGYE_SCOPE_GUARD_WITH_(g, i) for (int i = 1; i--; g)
+#define NEARGYE_SCOPE_GUARD_WITH(g)     NEARGYE_SCOPE_GUARD_WITH_(g, NEARGYE_STR_CONCAT(NEARGYE_INTERNAL_OBJECT_, NEARGYE_COUNTER))
+
+// SCOPE_EXIT executing action on scope exit.
+#define MAKE_SCOPE_EXIT(name)  auto name = NEARGYE_MAKE_SCOPE_EXIT
+#define SCOPE_EXIT             NEARGYE_MAYBE_UNUSED const MAKE_SCOPE_EXIT(NEARGYE_STR_CONCAT(NEARGYE_SCOPE_EXIT_, NEARGYE_COUNTER))
+#define WITH_SCOPE_EXIT(guard) NEARGYE_SCOPE_GUARD_WITH(NEARGYE_MAKE_SCOPE_EXIT{ guard })
+
+// SCOPE_FAIL executing action on scope exit when an exception has been thrown before scope exit.
+#define MAKE_SCOPE_FAIL(name)  auto name = NEARGYE_MAKE_SCOPE_FAIL
+#define SCOPE_FAIL             NEARGYE_MAYBE_UNUSED const MAKE_SCOPE_FAIL(NEARGYE_STR_CONCAT(NEARGYE_SCOPE_FAIL_, NEARGYE_COUNTER))
+#define WITH_SCOPE_FAIL(guard) NEARGYE_SCOPE_GUARD_WITH(NEARGYE_MAKE_SCOPE_FAIL{ guard })
+
+// SCOPE_SUCCESS executing action on scope exit when no exceptions have been thrown before scope exit.
+#define MAKE_SCOPE_SUCCESS(name)  auto name = NEARGYE_MAKE_SCOPE_SUCCESS
+#define SCOPE_SUCCESS             NEARGYE_MAYBE_UNUSED const MAKE_SCOPE_SUCCESS(NEARGYE_STR_CONCAT(NEARGYE_SCOPE_SUCCESS_, NEARGYE_COUNTER))
+#define WITH_SCOPE_SUCCESS(guard) NEARGYE_SCOPE_GUARD_WITH(NEARGYE_MAKE_SCOPE_SUCCESS{ guard })
+
+// DEFER executing action on scope exit.
+#define MAKE_DEFER(name)  MAKE_SCOPE_EXIT(name)
+#define DEFER             SCOPE_EXIT
+#define WITH_DEFER(guard) WITH_SCOPE_EXIT(guard)
+
+#endif // NEARGYE_SCOPE_GUARD_HPP